A comprehensive analysis has failed to find any evidence that Champix is associated with neuropsychiatric adverse events and adds to a strong body of evidence supporting the drug’s safety.

The safety of Champix has been debated for several years as a result of post-marketing reports of neuropsychiatric events such as depression, suicide thoughts and behaviour change. Many GPs and psychiatrists are still reluctant to prescribe Champix, especially in smokers with mental illness.

The study analysed 17 placebo-controlled randomised-controlled trials of varenicline (n=8,027), including two studies of smokers with a recent history of mental illness. Overall, 13% of the sample had a current or past psychiatric illness. The analysis found no significant effect of Champix on suicidal thoughts and behaviour, depression and aggression/agitation compared to placebo.

The study also included a re-analysis of data from a large cohort of smokers using either varenicline or nicotine replacement therapy (n=35,800). In this cohort, eight of the nine neuropsychiatric event types examined were less frequent in patients using varenicline than in those using nicotine replacement therapy.

The only disorder more frequently observed in varenicline-treated patients in the cohort study was ‘transient mental disorder’; however, there were very few of these events (0.05% for varenicline and 0.03% for nicotine replacement therapy) and the apparent difference was not statistically significant.

These findings were a valid for smokers with and without mental illness.

The Australian Association of Smoking Cessation Professionals (AASCP) welcomes these findings. According to Vice-President Dr Colin Mendelsohn, ‘Based on this evidence, GPs can confidently prescribe Champix, even in the setting of mental illness.’

‘Unfortunately, many patients have been denied the most effective stop-smoking medication because of these exaggerated concerns. Champix can save lives because it is more effective than other stop-smoking therapies, and helps some smokers to quit who would otherwise not have been able to do so’ Dr Mendelsohn said.

Dr Mendelsohn advises that GPs still follow the advice in the Australian guidelines, to inform patients that there have been some reports of neuropsychiatric side effects, but that if there is a risk it is very small. ‘Any risks from Champix should be balanced against the substantial health risks of smoking and the increased chance of success from using Champix’ Dr Mendelsohn says.

A likely explanation for the increased post-marketing reports of neuropsychiatric events for varenicline compared to NRT may have been the heightened media coverage and FDA warnings. Although the FDA had warned about drawing causal inferences from this data, many patients and health professionals became concerned.